WTP-101 Developing Web Applications with Standards · WTP-101 Developing Web Applications ......

WTP-101 Developing Web Applications © Copyright 2008 eteration a.s. WTP101-1

This course is made available under a Creative Commons Attribution-Share Alike 3.0 Unported License

© Copyright eteration a.s. 2008

eteration bilisim çözümleri ticaret a.s.

ITU Teknokent ARI-1 No:25

34469 Istanbul Turkey

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This course is made available under a Creative Commons Attribution-Share Alike 3.0 License

Copyright 2008, Eteration A.S.

1

WTP-101Developing Web Applications with Standards

using W3C org standard technologies such as, HTML, CSS, XML, XSD and XSL





2

Attributions

• World Wide Web Consortium– http://www.w3c.org

• Sandra Clark– CSS for Better Sites – CFUN04– http://www.cfconf.org/





3

Web Standards

Module Road Map

●Web Standards

●Web Architecture: Resources, URI and HTTP

●HTML and XHTML

●XML, XML Schemas and XML Parsing

●CSS

●XSLT





4

What are Web Standards

• Worldwide Web Consortium (W3C)– Recommends Standards for Web Development

• Recommendations:

Specifications for the Web's formats and protocols must be compatible with one another and allow (any) hardware

and software used to access the Web to work together

http://www.w3.org

Excerpt from w3c.org:

To achieve the goal of one Web, specifications for the Web's formats and protocols must be compatible with one another and allow (any) hardware and software used to access the Web to work together. W3C designs and promotes interoperable open (non-proprietary) formats and protocols to avoid the market fragmentation of the past.

Copyright © 2004-2005 W3C® (MIT, ERCIM, Keio), All Rights Reserved





5

w3c.org – The “one” web

• The W3C Technology Stack

Figure: http://www.w3.org/Consortium/technology

The W3C Technology Stack illustration depicts a model of two layers: the Web architecture (also labelled as “One Web”) built on top of the Internet architecture. The illustration fleshes out the middle Web layer by showing the areas of interest and technologies developed at W3C.

The Web architecture is depicted as a series of layers, each building on the other. From bottom to top, these layers contain:

* URI/IRI, HTTP

* Web Architectural Principles

* XML Infosets; RDF(S) Graphs

* XML, Namespaces, Schemas, XQuery/XPath, XSLT, DOM, XML Base, XPointer, RDF/XML, SPARQL

On top of these layers sit six boxes, corresponding to groups of major W3C Activities: Web Applications, Mobile, Voice, Web Services, Semantic Web, and Privacy.

The Interaction box lists XHTML, SVG, CDF, SMIL, XForms, CSS, and WCID.

The Mobile box lists XHTML Basic, Mobile SVG, SMIL Mobile, XForms Basic, CSS Mobile, MWI BP.

The Voice box lists VoiceXML, SRGS, SSML, CCXML, and EMMA

The Web Services box lists SOAP, XOP, WSDL, WS-CDL, and WS-A.

The Semantic Web box lists OWL, SKOS, and RIF.

The Privacy box lists P3P, APPEL, XML Encryption, XML Signature, and XKMS

A red and yellow banner (representing horizontal coordination at W3C) ties these four areas together and reads: Web Accessibility, Internationalization, Mobile Access, Device Independence, and Quality Assurance.

Copyright © 2004-2005 W3C® (MIT, ERCIM, Keio), All Rights Reserved





6

What Standards?

• Standards for the Web means:– Structural Languages

• HTML – Publishing Language of the Web• XHTML - Extensible Hypertext Markup Language 1.0 and 1.1• XML - Extensible Markup Language 1.0

– Transformations• XSL - Extensible Stylesheet Language• XPath – XML Path Language

– Presentation• CSS - Cascading Style Sheets Levels 1 and 2

– as well as emerging standards, such as those for television and PDA based User Agents





7

Web standards are important

• Designing and building with Web standards– Simplicity

• Simplifies and lowers the cost of production– Accessibility

• Delivers sites that are accessible to more people• Delivers sites that are accessible more types of Internet

devices. – Continuity

• Sites will continue to function correctly as traditional desktop browsers evolve, and as new Internet devices come to market

Quoted from http://www.webstandards.org mission statement





8

XML, HTML, XHTML, XSL & CSS

• XML for content– Most portable way to share and transfer information

• HTML/XHTML for publishable document structure– Structure does matter

• XSL for transformation– Transform between document types

• CSS for presentation– If it isn’t content it doesn’t belong in HTML





9

Standards Related

HTML doc presentation

XSL-FO

CSS

XSLT

XSLT

CSS

CSS

1

2

3XML doc

XML or HTML

HTML docHTML doc presentation

XSL-FO

CSS

XSLT

XSLT

CSS

CSS

1

2

3XML docXML doc

XML or HTMLXML or HTMLFigure: http://www.w3c.org

HTML – Hyper Text Markup Language

XML – Extensible Markup Language

XSLT - Extensible Stylesheet Language Transformations

CSS – Cascades Style Sheets

XSL-FO - Formatting Objects (i.e. For generating PDF from XML via XSLT)





10

Web Architecture

Module Road Map

●Web Standards


●HTML and XHTML


●CSS

●XSLT
















11

Section Goals

• To learn basic Web architecture• To learn how Resources, URI and HTTP are used to

access information on web servers





12

http

Simple Web Architecture

WTP 101Web Application

Develeopment

Resource

http://www.eclipse.org/webtools/education/101

Metadata:Content-type:application/xhtml+xml

Data:

<?xml version="1.0" encoding="utf-8"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>Web Tools Platform</title></head><body>..</body></html>

identify

repre

sent

URI

Representation





13

Http: Protocol of the Web

• The Internet consists of servers, clients, and routers– Servers provide the information– Clients use the information on the servers– Routers provide the network that allows clients and servers to

communicate

• Clients and servers typically communicate using HyperText Transfer Protocol (HTTP)

For the purposes of this course, it is not necessary to understand how routers work. Suffice it to say that the web is made up of routers that connect clients and routers and allow them to communicate with each other.

HTTP is used to transfer information such as web pages, images, etc. Other internet protocols include FTP (File Transfer Protocol - used for transferring files), Gopher, and Telnet. Since this course deals with web sites and web content, we will mostly be talking about HTTP.





14

Internet/Intranet

GET index.html

receive index.html

PC

Browser

Web Server

HTTPd

Docs

12

3

Simple HTTP• URI:

– The browser connects to the Web Server using a socket– The browser sends a “GET” request

• Resource:– The server resolves the request– Standard web pages are produced by the server

• Representation:– The HTML is sent to the browser– The socket is closed; the browser renders the document using HTML





15

Atomic Requests

• HTTP requests are non-conversational– A different socket is used to satisfy each request

• Traditional HTTP provides no mechanisms for multiple request relationships with clients

– Cookies can be used to maintain information about the client’s identity





16

What is an URL?

Scheme (http, ftp, gopher, ...)

Name of server

Port

Resource (name of page to download)

http://www.eteration.com:80/page.html

If you don’t specify a port, 80 is assumed.

• Uniform Resource Locator, or an address pointing to an Internet resource





17

The URL may be shown at the top of your browser as the "location" or "address"

Access the file /stuff/page.html from the server running on port 7001 on the local computer

http://localhost:7001/stuff/page.html

URLs

• A URL specifies the identity of the computer as well as the required resource

• File resources are specified relative to a “web root”– The “web root” is a directory on the server– The resource may include subdirectory information





18

Clients

• Clients access information provided by the servers– Web browsers are probably the most common web clients

• A client requests files by sending a HTTP request to server

– The request is sent over the internet using sockets– The file is specified in the request using a Uniform Resource Locator

(URL)





19

HTTP Request

• The request is formed by the client to inform the server of the request

• The request header includes:– Supported HTTP version, type of the requestor (User-agent), accepted

formats (Accept), accepted languages, cookies, ...

http://localhost:8080/stuff/page.html

Get /stuff/page.html HTTP/1.1Accept: text/htmlAccept-Language: en-usUser-Agent: Mozilla/4.0

sent to “localhost:8080”





20

Servers

• Web servers provide information to web clients– When a request comes in from a client, the server “serves” a response

• The response contains header information as well as the content of the page

• The type is contained in the header– This specifies what type of information is being returned in the response

(HTML page, an image, sound file, ...)– The client uses the type to decode the information in the response and

present it to the user





21

Server: JavaWebServer/1.0Content-Type: text/htmlSet-Cookie: id=954096

<HTML><BODY>Hello World!</BODY></HTML>

HTTP Response

• The server’s response includes a header followed by content data

– The client uses information in the header to determine what to do with the content

• The response header includes– Content type, content length, cookies, ...





22

MIME Encoding is not part of this course.

What is MIME?

• Multipurpose Internet Mail Extensions protocol– Standard for identifying and encoding binary data for transmission– Originally designed for sending e-mail attachments

• HTTP uses MIME – Identify the type of object in the response– Typically “text/html” which indicates that the return value is an HTML

document

• Browsers use this information to decide what to do with the content

– MIME also specifies a number of different encoding schemes for transporting 8-bit data over 7-bit protocols





23

MIME Types are case in-sensitive.

Some MIME Types

• Content types are specified as a type/subtype pair– Both the type and subtype are required

• text/html– The content of the message is HTML-formatted text

• text/plain– The content of the message is unformatted text

• image/jpeg– The content of the message is a JPEG image





24

Cookies

• Servers return additional information to the client via cookies

– Clients return the cookie information on subsequent requests

• Cookies can be used to maintain a relationship between a browser and the server

• Cookie’s life span can be configured– Live until a specified date and time– Live until the browser closes





25

A web site is a collection of related web pages.

Web Pages

• Web pages consist of text and HTML tags which provide formatting “suggestions” to web browsers

• Pages may contain images, movies, sounds, and other types of multimedia

• Pages may also contain client-side technologies– Java applets, JavaScript, ActiveX components which are downloaded

and executed on the client

• Pages can provide links to other pages– Links allow a user to move quickly and easily between related web

pages





26

Pages Can Be Static or Dynamic

• A web page may be an actual file located on a server– Static content

• Web pages may also be dynamically generated by the server

– Java servlets, Java Server Pages (JSPs)– Many, many others!





27

Dynamic Content

• Servlets and JSPs are accessed using a request with a URL - just like a regular page

• Unlike a regular page, the content in the response is generated dynamically by the servlet or JSP

• Servlets don’t just generate HTML!– Servlets can also be used to generate other MIME Types such as

images–

• Servlets are the subject of another course!





28

What You Have Learned

• The Internet consists of servers, clients, and routers• Web clients access information on web servers

using HyperText Transfer Protocol (HTTP)• Web pages contain text and multimedia • Web pages may be static or generated dynamically





29

Hands-On Lab

• Setup a Preview Server– Software is provided with WTP

• Create a simple page– Hello world will suffice

• Monitor HTTP traffic with TCP-IP Monitor– TCPIP Monitor is a proxy between the browser and the server





30

HTML and XHTML

Module Road Map

●Web Standards


●HTML and XHTML


●CSS

●XSLT
















31

Section Goals

• To learn Web standards for HTML and XHTML• To learn the structure of an HTML document • To learn how to use basic HTML tags





32

HTML Overview

• HTML stands for HyperText Markup Language• HTML files consist of text and tags

– Text provides the content of the page– Tags provide formatting "suggestions" to the client

• It is up to the client how these suggestions are implemented

• HTML tags are case-insensitive• Whitespaces within HTML files are generally ignored

– Formatting tags are used instead to specify line breaks, indentation, etc.

Text can have nested formatting tags applied to them. For example, the html: "Some <b><i>text</i></b> with multiple tags" would make the word "text" bold and italicized.

When using multiple tags on text, it is important that the start and end tags are properly nested. For example "<b><i>text</b></i>" is not allowed.





33

XHTML

• XHMTL is an xml compliant version of HTML 4.01• Benefits of using XHTML

– Easier to validate against– Because its more stringent, we are more careful– Requires the use of CSS for all presentation.– Standard across most User Agents





34

HTML vs. XHTML

• Element and Attributes– HTML

• <H1></H1>• <Input type=“Hidden”>

– XHTML must be lowercase• <h1></h1>• <input type=“hidden” />

• End tags are required– HTML

• <p>– XHTML

• <p></p>

• Empty Elements – HTML

• <br> , <hr>– XHTML

• <br/>, <hr />

• Quotes– HTML

• <input type=Hidden value=‘myvalue’>

– XHTML• <input type=“hidden”

value=“myvalue” />

• name/value pairs– HTML

• <input type=“checkbox” checked>

– XHTML• <input type=“checkbox”

checked=“checked”/>





35

DOCTYPE

• XHTML Documents must be well formed– MUST start with a <!DOCTYPE>

• User Agents (browsers) use the DOCTYPE– Choose what mode to use when rendering your HTML

<?xml version="1.0" encoding="utf-8"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>Web Tools Platform</title></head><body>..</body></html>

DocTypes are used for:

HTML Validation

Making sure your HTML is valid to the specification you state.

Rendering Modes

Standards Mode

Browsers will do their best to render your HTML according to the W3C recommendations

Quirks Mode

Browsers will try to render your HTML as it did before in its older browsers, including parsing errors, rendering errors and bugs..





36

Which mode am I in?

• To check which Rendering mode your computer is in, use the following:

– IE6 – Opera• javascript:alert(document.compatMode);

– CSS1CompatMode – Standards Based Rendering

– Firefox, Mozilla – Netscape• CTRL-I for page information.





37

Forcing User Agents• Force Standards Mode

– Example: HTML 4.x Strict<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "

http://www.w3.org/TR/html4/strict.dtd">

• Quirks Mode - XML declaration with the DocType– You need to use features from browser supports

• will Force IE6 and Opera into Quirks Mode– Avoid using <?xml version="1.0" encoding="UTF-8"?>

• Stay in standards mode– More Information: http://www.quirksmode.org/css/quirksmode.html

Quirks mode and strict mode are the two 'modes' modern browsers can use to interpret your CSS. Quirks mode refers to a technique used by some web browsers for the sake of maintaining backwards compatibility with web pages designed for older browsers, instead of strictly complying with W3C and IETF standards in standards mode.

http://en.wikipedia.org/wiki/Quirks_mode

http://www.quirksmode.org/css/quirksmode.html





38

This shows some <b>bold</b> text.

HTML Tags

• Most tags have a start tag that indicates the start of the formatting and an end tag to specify the end

– Start tags are of the form <tag>– End tags are of the form </tag>

• The formatting applies to the text between the start and end tag

• Some tags also have attributes which provide more information within the start tag

– Attribute values may use single or double quotes– Single quotes will make your life easier later...





39

Page Structure Tags...

• Tags used to specify the structure of the page– Pages have a head and a body

• Pages start with a <html> and end with a </html> – Tells the browser what type of file it is

• The <head> tag comes at the top of the page– May contain a <title> tag

causes the window name to be changed while the page is being displayed

• The <body> tag follows the <head></head> tags– The body contains the content of the page





40

...Page Structure Tags

<html> <head> <title>Page title</title> </head> <body> <h1> Header</h1> ...Page content... <h2>Subtitle</h2> ...More content... </body></html>





41

By default, text is left-justified

Basic Formatting Tags...•  - Comment • <b> - Bold text• <i> - Italicized text• <u> - Underlined text• <br/> - Add a line break to the text• <hr/> - Add a line break and header rule• <p> - Paragraph

– <p align=“right” > - Start a new right-justified paragraph

• <h1> - Text is formatted as a level-1 heading– Can also use <h2>, <h3>, <h4>, <h5>, and <h6>

• <center> - Text contained in these tags is center-justified





42

...Basic Formatting Tags

Paragraph tags should have an end tag!

<html> <head> <title>Eteration!</title> </head> <body> <h1>Welcome to Eteration!</h1> <hr /> <p>Training<br /> Consulting</p> <p>Products</p> <hr /> </body> </html>





43

<table border=“2”> <tr><th>Employee</th> <th>ID</th> <th>Phone#</th></tr> <tr><td>Tom Johnson</td><td>45938</td><td>432-7548</td></tr> <tr><td>Steve Smith</td><td>12450</td><td>349-9832</td></tr> <tr><td>Dan Jones</td><td>34545</td><td>887-3492</td></tr> </table>

Table Tags

• A table is specified by providing tags for each row; the columns are specified with each row

• Tags:– <table> - Creates an HTML table– <tr> - Starts a new row within a table– <td> - Starts a new cell within a table row– <th> - A heading cell within a table





44

HTML Lists

• HTML has tags that output text in a list format– <ul> - Unordered (bullet) list– <ol> - Ordered (numbered) list– <li> - Start a new entry in a list (ordered or unordered)

Shopping list: <ul> <li>Oranges</li> <li>Bananas</li> <li>Faux-fu (Tofu substitute)</li> </ul>

Things to do: <ol> <li>Do groceries</li> <li>Get a hair cut</li> <li>Clean the house</li> </ol>





45

Click<a href="http://www.eteration.com/education/">here</a> to go to education pages.

White space is ignored by HTML formatters

HTML Links

• Create a hyperlink using the <a> tag• This tag has one attribute call href

– Used to specify the URL of the location to link to

• The link can refer to an HTML page, a servlet, an image, ...





46<img src="images/eteration400.gif" alt=“Eteration Logo” />

The Image Tag

• Image tags are used to display graphical images• The image tag can have a number of different

parameters• “src”

– The source URL of the image; the browser will use this URL to make a request for the image

• “alt”– Specifies alternative text to display if the browser can’t (or won’t) display

the graphic

• “height” and “width”– Used to customize the size of the image without altering the source file

An alternate low resolution file can also be specified using the “LOWSRC” parameter

The low resolution file is loaded first and then replaced by the high resolution version when it is loaded.

Images can be marked as hyperlinks by surrounding the image specification with <a href=...> </a> tags





47


• How a web page is structured• How to use basic HTML tags• How to add lists and hyperlinks to your HTML pages





48

Hands-On Lab

• Create a Web page– XHTML Transitional 1.0– Validate XHTML at http://validator.w3.org/

• Use tables for layout• Use tables for listing objects• Tables are very complex to work with.

– We will fix some of the problems later





49

XML and XML Schemas

Module Road Map

●Web Standards


●HTML and XHTML

●XML and XML Schemas

●CSS

●XSLT
















50

Section Goals

• To learn about XML• Compare HTML, SGML and XML• To learn about DTDs• To learn about XSDs• To learn basic XML parsing techniques an APIs





51

Common Terms

• XML: eXtensible Markup Language

• XSD: XML Schema Definition

• DTD: Document Type Definition





52

SGML Background

• Standard Generalized Markup Language (ISO 8879)– Motivated by heavy document processing requirements of large

organizations– Exchange text without loosing “structure”– Complex failed to gain wide acceptance

• Both XML and HTML came form SGML

SGMLISO8879 -1986

HTML1989

XML1996

SGML is the International Standard (ISO 8879) language for structured data and document representation, the basis of HTML and XML and many others. First Introduced by Charles Goldfarb in 1974, ISO 8879 was published on October 15, 1986 (http://www.iso.org). http://www.w3.org/XML/

SGML emforces highly structured documents. SGML’s descriptive markup system allows markup codes to provide names and categorize parts of a document. Markup codes such as <para> or \end{list} simply identify a portion of a document and assert of it that ``item is a paragraph,'' or ``end of the list,'' etc. The structure of any SGML document is described by a Document Type Declaration (DTD). SGML parsers may use DTD to validate the contents of a SGML document. In SGML it is easy to keep the contents separated from any formatting information. SGML introduces the notion of a document type, and hence a document type definition (DTD). Documents are regarded as having types, just as other objects processed by computers do. The type of a document is formally defined by its constituent parts and their structure. The definition of a report, for example, might be that it consisted of a title and possibly an author, followed by an abstract and a sequence of one or more paragraphs. Anything lacking a title, according to this formal definition, would not formally be a report, and neither would a sequence of paragraphs followed by an abstract, whatever other report-like characteristics these might have for the human reader. If documents are of known types, a special purpose program (called a parser) can be used to process a document claiming to be of a particular type and check that all the elements required for that document type are indeed present and correctly ordered. More significantly, different documents of the same type can be processed in a uniform way. Programs can be written which take advantage of the knowledge encapsulated in the document structure information, and which can thus behave in a more intelligent fashion. SGML documents are encoded and should be transportable from one hardware and software environment to another without loss of information.





53

Format Markup vs. Structure Markup

• Meaning comes with structure– How can you tell the name of this person?

Naci Daieteration a.s.

25 ITU ARI-1 Teknokent Maslak Istanbul

34469Turkey

Arial 24pt Bold

Lucida 24pt Orange

Times Roman 18pt

Times Roman Bold 18pt

Name

Company

Address

Times Roman Bold 18pt

Postal Code

Country

Format Structure

Markup Identifies Elements of a Document





54

HTML is Limited

• Simple markup language– Not designed for structuring data

• Result:– Not for arbitrary universal custom data

Multi ChannelDelivery

different Presentation media

StructureArbitrary Data

IntegrateRemote heterogenous

Systems

Evolution

Web

HTML





55

What is XML?

• EXtensible Markup Language• XML is a metadata language

• Data is:– Web page– Printed Book– Product

• Metadata is:• Information about data (data about data)• Describing what the data is, identifying content

Extensible Markup Language, abbreviated XML, describes a class of data objects called XML documents and partially describes the behavior of computer programs which process them. XML is an application profile or restricted form of SGML, the Standard Generalized Markup Language [ISO 8879]. By construction, XML documents are conforming SGML documents. XML documents are made up of storage units called entities, which contain either parsed or unparsed data. Parsed data is made up of characters, some of which form character data, and some of which form markup. Markup encodes a description of the document's storage layout and logical structure. XML provides a mechanism to impose constraints on the storage layout and logical structure. A software module called an XML processor is used to read XML documents and provide access to their content and structure. XML was developed by an XML Working Group (originally known as the SGML Editorial Review Board) formed under the auspices of the World Wide Web Consortium (W3C) in 1996.

The design goals for XML are:

XML shall be straightforwardly usable over the Internet.

XML shall support a wide variety of applications.

XML shall be compatible with SGML.

It shall be easy to write programs which process XML documents.

Optional features in XML is to be kept to the absolute minimum, ideally zero.

XML documents should be human-legible and reasonably clear.

The XML design should be prepared quickly.

The design of XML shall be formal and concise.

XML documents shall be easy to create.

Terseness in XML markup is of minimal importance.

Source: http://www.w3.org/TR/REC-xml please see the copyright statement on the site





56

XML is Extensible

• Define your own tags– There is no single set of XML tags– Unlike HTML, where there is a core set of tags

• Comprimising extensibility HTML is easy to learn and use

<address><name>Naci Dai</name><company>Eteration</company><street>25 ARI-1 ITU Teknokent</street><zip>34469</zip><country>Turkey</country>

</address>

<order><price>10$</price>..</order>

<message><text>Hello</text>..</message>

html xml

<html> <head> <title>Eteration</title> </head> <body> <br /> <h1>Hello!</h1> </body> </html>





57

<?xml version="1.0" encoding="UTF-8"?>

<address>

<name>Naci Dai</name>

<company>Eteration</company>

<suite>25</suite>

<street>ITU ARI-1 Teknokent</street>

<zip>34469</zip>

<city>Istanbul</city>

<country>Turkey</country>

</address>

XML is for Markup

• Markup is identifying disctinct elements of documents

– Essential for documents to make sense

John SmitheterationSuite 25. ITU ARI-1 TeknokentISTANBUL34469 Turkey

Plain textxml

markup





58

XML is a Language

• XML is a formal document markup language• A document has a physical and logical structure

– Physical: • Composed of units called entities thay may refer to others • There is a "root" or document entity

– Logical• Composed of declarations, elements, attributes, comments,

character references, and processing instructions

• XML has syntax– Indicated in the document by explicit markup– The logical and physical structures must nest properly





59

XML Elements

<invoice>

<from>ABC TELECOM, Inc.</from>

<to>John Smith</to>

<description>Local Phone Service</description>

<date type="from">16 May 1999</date>

<date type="to">15 Jun 1999</date>

<date type="due">15 Jul 1999</date>

<amount>$50.00</amount>

<taxRate>6</taxRate>

<totalDue>$53.00</totalDue>

</invoice>

Element describes data– One can define any element– Element can contain other elements– An element is terminated by </…>





60

XML Attribute

• Describe an element

• Cannot contain other elements or attributes


<invoice type="bill" period="monhly">

<from>ABC TELECOM, Inc.</from>

<to>John Smith</to>

<description>Local Phone Service</description>

<date type="from">16 May 1999</date>

<date type="to">15 Jun. 1999</date>

<date type="due">15 Jul. 1999</date>

<amount currency="USD ">$50.00</amount>

<taxRate>6</taxRate>

<totalDue>$53.00</totalDue>

</invoice>

• Describes an element– One can define any attribute – Cannot contain other elements or attributes





61

Grammars for XML Documents

• Two current standards for constraining XML with grammars

– DTD (Document Type Definition) – XML Schema





62

DTD: Document Type Definition

• DTD– defines document structure– makes XML data usable for different programs– can be declared inline or as external reference

• Internal DOCTYPE declaration• <!DOCTYPE root-element [element-declarations]>

• External DOCTYPE declaration• <!DOCTYPE root-element SYSTEM "filename">

DTDs originate from SGML and they are not XML-like

hint: When possible use XML Schemas





63

DTD Example<?xml version="1.0"?><!DOCTYPE email [ <!ELEMENT email(to+, from, subject, message)> <!ELEMENT to (#PCDATA)> <!ELEMENT from (#PCDATA)> <!ELEMENT subject (#PCDATA)> <!ELEMENT message(#PCDATA)>

]> email.dtd

<?xml version="1.0"?><!DOCTYPE email SYSTEM “email.dtd"><email> <to>[email protected]</to> <from>[email protected]</from> <subject>Important</subject> <message>Hello!!!</message>

</email> email.xml



What is an XML Schema?

The purpose of an XML Schema is to define the legal building blocks of an XML document, just like a DTD.

An XML Schema:

defines the elements that appear in a document

defines attributes that can appear in a document

defines which elements are child elements

defines the order of child elements

defines the number of child elements

defines whether an element is empty or can include text

defines data types for elements and attributes

defines default and fixed values for elements and attributes



64

XSD : XML Schema Definition

• XSD : XML Schema Definition– Is an XML language for describing and constraining the content of XML

documents. – Alternative to DTD

• XSD: specifies structure of XML document i.e.– elements and attributes in the XML doc– XML element hierarchy– element data-types and occurrences

• http://www.w3.org/2001/XMLSchema





65

Types and Elements

• XSD schemas contain type definitions and elements– Type definitions define XML data type

• address, customer, purchaseOrder,...– Elements represent items created in the XML file

• If the XML file contains a PurchaseOrder type, then the XSD file will contain the corresponding element named PurchaseOrder.





66

XSD template

<?xml version="1.0" encoding="UTF-8"?><xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.eteration.com" xmlns:tns="http://www.eteration.com" elementFormDefault="qualified"></xs:schema>

1 – Elements and data-types used come from here. Prefix these elements with xs

2 – Elements defined in this schema have this namespace.3 – Default namespace4 – Must be namespace qualified

1

23

4





67


<m:message

xmlns:m="http://www.example.org/message"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://www.example.org/message message.xsd">

<m:to>Derya</m:to>

<m:from>Esma</m:from>

<m:subject>Please call</m:subject>

<m:text>Call me ASAP</m:text>

</m:message>

XML referencing an XSD

• Corresponding xml references xsd.• Validation checks formation and cross checks XML against

XSD

xsd namespace ref xsd file





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Namespaces

• XML Namespaces provide a method to avoid element name conflicts

– a name conflict will occur when two different documents use the same element names.

• Every XML Schema uses at least two namespaces– targetNamespace – XMLSchema namespace

• http://www.w3.org/2001/XMLSchema





69

Need for Namespaces

<?xml version="1.0" encoding="ISO-8859-1" standalone="yes"?><book>  <title> Eclipse Web Tools Platform</title>

<figure>  <title>Simple Web Architecture</title>

<ns1:book xmlns:ns1="http://example.org/book"> <ns1:title>Eclipse Web Tools Platform</ns1:title> <ns2:figure xmlns:ns2="http://example.org/book/figure"> <ns2:title>Simple Web Architecture</ns2:title>

AmbigousW

ith namespace





70

Namespace Syntax

• Two parts– Namespace declaration

– Elements and attributes

• Declaration– A prefix is associated with URI– The association is defined as an attribute within an element

xmlns:prefix– xmlns is Namespace keyword, prefix is user-defined

<classes xmlns:XMLclass=“http://www.example.org/test”> <XMLclass:syllabus> ... </XMLclass:syllabus></classes>





71

Namespace Declaration

• Can be declared in:– root element – lower level element

• Multiple different namespaces can be defined

• Same prefix can be redefined – Scope of Namespace declaration is within the element where it is

defined





72

Elements and attributes

• Examples– svg:set

– mathml:set

prefix: local part– prefix identifies the namespace an element and attribute belongs to

– local part identifies the particular element or attribute within the namespace

– Qualified name

• Naming rules:– Prefix can be composed from any legal XML name character except “:”

– “xml” (in any case combination) is reserved so cannot be used as prefix– Local part cannot contain “:”





73

Namespace URI

• URI cannot be prefix– “/”, “%”, and “~” are not legal in XML element names

• URI could be standardized – (by industry standard orgs) while prefixes are just convention

• URI are just “identifiers”– URI does not have to be in “http” form

– URI does not have to be resolved

– It is like a “constant value”





74

Default Namespace

• Denoted with xmlns attribute with no prefix– Applied only to unprefixed element and its descendant elements

• Applies only to elements not attributes

<?xml version="1.0"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:xlink="http://www.w3.org/1999/xlink"> <head><title>Three Namespaces</title></head> <body> <h1 align="center">An Ellipse and a Rectangle</h1> <svg xmlns="http://www.w3.org/2000/svg" width="12cm" height="10cm"> <ellipse rx="110" ry="130" /> <rect x="4cm" y="1cm" width="3cm" height="6cm" /> </svg>





75

Types of Namespaces

• target Namespace– Namespace for XML Schema document itself

• source Namespaces– Definitions and declarations in a schema can refer to names that may

belong to other namespaces

<xsd:schema targetNamespace='http://www.SampleStore.com/Account' xmlns:xsd='http://www.w3.org/1999/XMLSchema' xmlns:ACC= 'http://www.SampleStore.com/Account'>

<xsd:element name='InvoiceNo' type='xsd:positive-integer'/> <xsd:element name='ProductID' type='ACC:ProductCode'/> <xsd:simpleType name='ProductCode' base='xsd:string'> <xsd:pattern value='[A-Z]{1}d{6}'/> </xsd:simpleType>



targetNamespace is the namespace that is going to be assigned to the schema you are creating. It is the namespace an instance is going to use to access the types it declares.

The default namespac applies to the element that declares it, and its child elements, unles they are prefixed. In the example, all the elements belong to the default namespace, except addr:street. Since it is prefixed, it belongs to the addr namespace



76

targetNamespace

• The namespace that is assigned to the schema created– The names defined in a schema are said to belong to its target namespace– The namespace an instance is going to use to access the types it declares

• Each schema has:– One target namespace – Possibly many source namespaces





77

Defining Types

• Types may be simple or complex– SimpleTypes

• cannot contain elements or have attributes• are types that are included in the XML Schema definition (boolean,

string, date, etc.)– ComplexType

• can contain attributes and elements





78

Common XML Schema Data Types

– string– boolean– decimal– float– double

– duration– dateTime– time– date





79

XSD: SimpleType Example

<simpleType name="name"><restriction base="string"></restriction><xs:pattern value="([a-z][A-Z])+"/>

</simpleType>

• More Restriction Specs:

<xs:restriction base="xs:integer"> <xs:minInclusive value="0"/> <xs:maxInclusive value=“100"/> <xs:pattern value="[0-9][0-9][0-9]"/>

</xs:restriction>

• Describes the data allowed in a Simple Field:

• Constraints: enumeration, length, minLength, whitespace etc.





80

XSD: ComplexType Example

• Similar to defining a Java class or a Data Structure– Can use own types

<complexType name="PersonType"> <sequence>

<element name="name" type="string"/><element name="surname" type="string"/><element name="address" type="tns:AddressType"/><element name="phoneNumber" type="tns:PhoneType" />

</sequence></complexType>





81

Type & Element

• Name the Type if it will be used again

<xs:complexType name="AddressType"><xs:sequence> <xs:element name="street1" type="xs:string" /> <xs:element name="street2" type="xs:string" /> <xs:element name="postcode" type="xs:string" /> <xs:element name="city" type="xs:string" /></xs:sequence>

</xs:complexType>

<xs:element name="shippingAddress" type="tns:AddressType" /><xs:element name="invoiceAddress" type="tns:AddressType" />





82

XSD: Indicators<xs:choice> <xs:element name="employeeName" type="xs:string"/> <xs:element name="employeeNum" type="xs:integer"/> </xs:choice>

<xs:element name="person" maxOccurs="unbounded"> <xs:complexType> <xs:sequence> <xs:element name="full_name" type="xs:string"/> <xs:element name="child_name" type="xs:string" minOccurs="0" maxOccurs="5" />

</xs:sequence> </xs:complexType>

</xs:element>

• Order– all

• Not ordered– choice

• One of– sequence

• Ordered

• Multiplicity– minOccurs / maxOccurs - Use unbounded for open boundary





83

Importing a Schema

• Reuse and refactor XSD documents– Partition namespaces– Use existing schemas

• Import– XSD is not same namespace

• Include– XSD is the same namespace

<?xml version="1.0" encoding="UTF-8"?><xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:store= "http://www.store.com/store" xmlns:catalog="http://www.partner.com/catalog">

<xs:import namespace='http://www.partner.com/catalog' schemaLocation='http://www.partner.com/catalog.xsd'/>

<xs:element name='stickyGlue' type='catalog:SuperGlueType'/>





84


• XML– standard for data interchange– was designed to describe data and to focus on what data is – text-based– does not define tags of its own





85

Hands-On Lab

• Create a Schema for the ObjectShop catalog– Use WTP XSD Editor

• Create Sample Catalogs• Validate catalog files using XSD





86

CSS

Module Road Map

●Web Standards


●HTML and XHTML


●CSS

●XSLT
















87

What is CSS?

• CSS: Cascading Style Sheets – The method used to divide the content from the presentation on web

pages.

• Styles – define how to display HTML elements – normally stored in Style Sheets





88

Recall: Standards Related

HTML doc presentation

XSL-FO

CSS

XSLT

XSLT

CSS

CSS

1

2

3XML doc

XML or HTML

HTML docHTML doc presentation

XSL-FO

CSS

XSLT

XSLT

CSS

CSS

1

2

3XML docXML doc

XML or HTMLXML or HTMLFigure: http://www.w3c.org

HTML – Hyper Text Markup Language

XML – Extensible Markup Language

XSLT - Extensible Stylesheet Language Transformations

CSS – Cascades Style Sheets

XSL-FO - Formatting Objects (i.e. For generating PDF from XML via XSLT)





89

CSS Design Benefits

• Maintenance and Flexibility– Cleaner / Less code– Refactor presentation reduce repetitive styling– Better document structure

• Accessible– Structure is separated from presentation– Ability to present content on multiple devices such as mobile handhelds

and formats (printer-friendly etc.)

• Faster download times and smaller pages– Tableless layouts, no repetition, all styles in one place





90

CSS Syntax

• The CSS syntax is made up of two parts: – Pattern– Rule

• Rule is made of– property – value

pattern rule

p { text-align: center; color: black; font-family: arial}

h1,h2,h3 { color: red}

{property: value}





91

CSS Pattern Matching: Selectors

• Match things in a document to apply a rule– Document elements– Elements with specific ids– Element with specific classes

• More than one pattern can be associated with a rule– Separated with comma

h1 , h2, h3 { color: red}





92

CSS2 Selector Patterns

• Pattern matching rules determine which style rules apply to elements in the document tree.– Patterns are called selectors that range from simple element names to

rich contextual patterns.– If all conditions in the pattern are true for a certain element, the selector

matches the element.

• Some examples of selectors– Type Selectors– Class and ID Selectors– Descendant and Child Selector– Universal Selector– Adjacent Selectors– Attribute Selectors

See: http://www.w3.org/TR/CSS2/selector.html#q2





93

Type Selectors

• Matches the name of a document(html) element type– The following rule matches all H1 elements in the document tree:– h1 { font-family: sans-serif }

<style type="text/css">p{ text-align: left; color:"red"; font-size: 20px; }</style>...<p>This is first paragraph </p><p>This is second paragraph </p>

This is the first paragraphThis is the second paragraph





94

Class Selectors

• Match all elements with the given class attribute– Specified with ‘.’ before the class name– Only one class attribute can be specified per HTML element

• Examples– p.article - All paragraphs with a class of “article”– .error - Any element with a class of “error”.

p.first{ text-align: left; color:"red"; font-size: 20px; }p.second{ text-align:left; color:"blue"; font-size: 16px; }...<p class="first">This is first paragraph </p><p class="second">This is second paragraph </p>

This is the first paragraphThis is the second paragraph





95

ID Selectors

• Matches the given id attribute– An id must be unique in a page.– Use a # in the selector

• Examples– div#menu - selects the div element with the id of “menu”– #header - selects the element with the id of “header”.

#redtext{ text-align: left; color:"red"; font-size: 20px; }

<p id="redtext">This is first paragraph </p>

This is the first paragraph

...<h1 id="redtext">This is a header

This is a header

Another page





96

Descendant Selectors

html

bodyhead

table

tr

td

p

tr

td

p

h1

• Match an element that is the descendant of another element in the document tree

Examples:• body p {font-weight:bold;}

– Any paragraph text which is a descendant of body

• tr td p {color: red;}

Also known as contextual selectors,

Descendant selectors allow us to apply rules in certain structural elements, but not others.

Style only those em classes that are descended (appear within) a paragraph element.

Translate the space as “found within”

p em translates to “apply these rules to all emphasis elements found within p elements.

You may append as many selectors for a descendant selector as you want, you aren’t limited to 2.





97

Child Selector

html

bodyhead

table

tr

td

p

tr

td

p

h1

• Matches when an element is the child of another element

tr > td > p{ color: green;}

You may combine descendant and child combinations in the same selector.

Doesn’t work in IE





98

Adjacent Selectors

html

bodyhead

table

tr

td

p

tr

td

p

h1

• Selects an element that follows another element

– Text between tags have no effect

• Example:– h1 + table { width: 100%; }

Select any paragraph immediately following an h1 element.

In order to work properly, CSS requires that the two elements appear in source order.

You may use the adjacent-sibling combinator in conjunction with any other combinators.

Some browsers (IE Opera) have issues with this.

They will often just match the last selector in the expression





99

Universal Selectors

• Matches an element that is a grandchild or later descendant of another element.

– Selects paragraphs that are at least one selector removed – Note spaces before and after *

• div * p– p element that is a grandchild or later descendant of a div





100

Attribute Selectors

• Attribute selectors may match in four ways:• [att]

– The "att" attribute is set, whatever the value of the attribute.

• [att=val]– "att" attribute value is exactly "val"

• [att~=val]– "att" attribute value is a space-separated list of "words", one of which is

exactly "val"

• [att|=val]– "att" attribute value is a hyphen-separated list of "words", beginning with

"val" • This is primarily intended to allow language subcode matches (e.g.,

the "lang" attribute in HTML)

http://www.w3.org/TR/CSS2/selector.html#attribute-selectors

Not supported in IE6





101

Getting documents ready for CSS

• CSS is case sensitive:– HTML names should match match the name of the selector exactly.– <p class=“red” /> does not match p.Red{}–

• Use ids and class attributes to mark elements– No spaces– <input id=“first-name” />– <input id=“last-name” />





102

Inserting a style sheet

• Three ways of inserting a style sheet– External Style Sheet – Internal Style Sheet – Inline Styles





103

External Style Sheet

• An external style sheet is ideal – when the style is applied to many pages

• Link to the style sheet using the <link> tag. – The <link> tag goes inside the head section

• Style sheet file – should be saved with a .css extension– should not contain any html tags

<head><link rel="stylesheet" type="text/css" href="mystyle.css" /></head>

<body><p class="first">This is first paragraph</p><p class="second">This is second paragraph</p></body>





104

Internal Style Sheet

• Internal Styles– should be used when a single document has a unique style– Is defined by using <style> tag in the head section

<head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1“ />

<style type="text/css"> p {color: white; } body {background-color: black; }</style>

</head>





105

Inline Styles

• Placing CSS in the HTML code• This method should be used sparingly

– For example, when a style is applied to a single occurrence of an element.

<p style="background: black; color: white;">This is new background and font color with inline CSS </p>





106

Cascading Order

• Styles will "cascade" by the following rules

– Browser default – External Style Sheet – Internal Style Sheet– Inline Style

highest priority

lowest priority





107

CSS Background

• Defines the background effects on an element

– background • all background properties in one declaration.

– background-attachment • sets whether a background image is fixed or scrolls with the rest of the page.

– background-color • background color of an element

– background-image • Sets an image as the background

– background-position • sets the starting position of a background image

– background-repeat • sets if/how a background image will be repeated





108

CSS Background Examples

h4 { background-color: white; }

body{ background-image: url(point.gif);background-repeat: repeat-x}

p { background-image: url(smallPic.jpg); }

body { background-image: url(stars.gif); background-attachment: scroll}





109

CSS Text

• Defines the spacing, decoration, and alignment of text

• Properties– color– direction– letter-spacing– text-align– text-indent– text-decoration– white-space– word-spacing

h2{ text-decoration: underline; }

p { text-indent: 20px; }





110

CSS Font

• Defines the font in text• Properties

– font– font-family– font-size– font-style– font-weight– ...

p { font: italic small-caps bold 12px arial }

p { font-size: 12px; }

ol{ font-size: 10px; }

p { font-style: italic; }

ul{ font-weight: bolder; }





111

CSS Border

• Allows for complete customization of the border that appear around HTML elements

• Properties– border– border-color– border-style– border-bottom– border-bottom-color– border-bottom-style– border-bottom-width– ....

table {

border-width: 7px; border-style: outset; }

td {

border-width: medium; border-style: outset; }

p {

border-width: thick; border-style: solid; }





112

CSS Margin

• Defines the space around the elements • Properties

– margin– margin-bottom– margin-left– margin-right– margin-top

h5{ margin-top: 0px;margin-right: 10px;margin-bottom: 10px;margin-left: 10px;border: 3px solid blue; }





113

CSS and Tableless Layouts

• You can use CSS to do tableless layouts– float– Position: fixed (position absolute)– HTML <div> tags





114

DIV Based Page Layout with CSS

• Table-based layouts are common• Use div tags and CSS

– Reduces markup code– Separates content from its visual

presentation

• DIV tag– Used as a container within our Web page– Creating sections or divisions

Header

Footer

MiddleSidebar





115

Div Example

<body>

<div id="headerregion"></div>

<div id="middleregion">

<div id="sidebar"></div>

<div id="middle"></div>

</div>

<div id="footerregion"></div>

</body>

Header

Footer

MiddleSidebar





116

Liquid Page Designs

• Fixed Locations (position)

• Flow around (float)

div#headerregion {position: absolute;width: 100%;top: 0;left: 0;height: 50px;

}/* position:fixed for modern browsers (IE 7 / Firefox) NO scroll */body > div#headerregion {

position: fixed;}

div#sidebar {width: 180px;float: left;

}





117


• Cascading Style Sheets are a way to control the look and feel of your HTML documents in an organized and efficient manner.

• With CSS you will be able to– Add new looks to your old HTML – Completely restyle a web site with only a few changes to CSS code





118

Hands-On Lab

• Create a CSS to manage look-and-feel of a site• Manage Layout using <div> regions instead of

tables





119

XSLT

Module Road Map

●Web Standards


●HTML and XHTML


●CSS

●XSLT
















120

XSLT

• Extensible Stylesheet Language Transformations• Transform XML documents into:

– XML, XHTML, HTML, ..

• Generate an output from two input files:– Content: An XML document– Transformation: An XSL document that contains the “template” and XSL

transformations to insert content from XML

• XSL is a programming language– NOT a simple one– Debugging your XSL





121

XSL - Hello World

• XML: helloworld.xml

• XSL: helloworld.xsl:

<?xml version="1.0"?><?xml-stylesheet type="text/xsl" href="helloworld.xsl"?><message>Hello World!</message>

<?xml version="1.0"?><xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">  <xsl:output method=“html” /> <xsl:template match="/"> <html> <body> <h1> <xsl:value-of select="message" /> </h1> </body> </html> </xsl:template></xsl:stylesheet>

Result file:

<html> <body> <h1> Hello World! </h1> </body></html>





122

Anatomy of the XSL file

<?xml version="1.0"?><xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<xsl:output method=“html“ /> <xsl:template match="/"> <html> <body> <h1> <xsl:value-of select="message" /> </h1> </body> </html> </xsl:template>

</xsl:stylesheet>

Start

End

Contains multiple templates

Content-type of output





123

How did we get to text in the message?

Templates

• Alternative select statements– ./message– with XPath functions

• /message/text()• ./message/text()

<xsl:template match="/"> <html> <body> <h1>

<xsl:value-of select="message" /> </h1> </body> </html>

</xsl:template>

Select the root node in XML

Select the messagechild and write

write to output

write to output





124

Inside the XSLT Transformation

1. Read the XML document and store it as a Tree of nodes

3. Match templates to parts of the tree– <xsl:template match="/"> select the entire tree– <xsl:template match=“..."> use it to select subsets

4. Apply the rules in each the template to create a new structure– <xsl:apply-templates/> Call additional templates from the root template

5. Unmatched parts of the XML tree are not changed

7. Write the transformed tree as a text document





125

XSL can run on the server and the client

• Server:– Xalan, Saxon, Xerces, etc. can be used to read and write files– Use XSLT to change XML files into HTML files before sending them to

the client– More portable (Less to expect from a browser)

• Client– A modern browser can use XSLT to change XML into HTML on the

client side– Internet Explorer 6+– Netscape 6+– Mozilla, Firefox 1+, Opera 8+, ..





126

xsl:value-of

<xsl:value-of select="XPath expression"/> • selects the contents of an element and adds it to the

output stream– The select attribute is required– Notice that xsl:value-of is not a container, hence it needs to end with a

slash

• Example:<h1> <xsl:value-of select="message"/> </h1>





127

xsl:for-each

Loop statement<xsl:for-each select="XPath expression">

Text to insert and rules to apply</xsl:for-each>

• Example: Select all books (//book) and list the titles (title):

<ul> <xsl:for-each select="//book"> <li><xsl:value-of select="title"/></li> </xsl:for-each> </ul>





128

Filtering output

Filter output with a criteriontitle[../genre='mystery'] Legal filter operators are:

= != < >

Example: Select all school books (//book) and list the titles (title):<ul> <xsl:for-each select="//book">

<li> <xsl:value-of select="title[../genre='mystery']"/> </li> </xsl:for-each></ul>

title and genre are at the same level of the XML tree (they are both inside the book). “../ “ takes us to the level of the book and we select “genre”

There is a catch! Other items will also show in the list as empty items





129

But it doesn’t work right!

<xsl:for-each select="//book"><li> <xsl:value-of select="title[../genre='mystery']" /></li>

</xsl:for-each>

outputs for every book,– Empty bullets for other books– Do not use xsl:value-of to filter

Alternative Filter:<xsl:for-each select="//book[./genre='mystery']">

<li> <xsl:value-of select="title" /></li>

</xsl:for-each>OR





130

xsl:if

• Include content when condition is true• Example:

<xsl:for-each select="//book"><xsl:if test="genre='mystery'" > <li>

<xsl:value-of select="title" /> </li> </xsl:if>

</xsl:for-each>





131

xsl:choose

• XSL switch ... case ... default statement• The syntax is:

<xsl:choose> <xsl:when test="some condition"> ... some code ... </xsl:when> <xsl:otherwise> ... some code ... </xsl:otherwise></xsl:choose>





132

xsl:sort

• Sorting inside an xsl:for-each– Attribute of the sort tells what field to sort on

• Example: <ul> <xsl:for-each select="//book"> <xsl:sort select="author"/> <li> <xsl:value-of select="title"/> by <xsl:value-of select="author"/>

</li> </xsl:for-each> </ul>





133

xsl:text

• <xsl:text>...</xsl:text> helps with:– Whitespaces and special characters

<xsl:text disable-output-escaping="yes"> </xsl:text>





134

Creating tags from XML data

• XML <label>Eteration A.S.</label><url>http://www.eteration.com</url>

• Desired Result <a href="http://www.eteration.com">

Eteration A.S.</a>

• We cannot use invalid XML within XSL– <xsl-valueof> does not work inside a tag– Same with <img /> tags





135

Solutions

Using: <xsl:attribute name="...">

<a> <xsl:attribute name="href">

<xsl:value-of select="url"/></xsl:attribute><xsl:value-of select="label"/>

</a>

Using attribute value template: {...}

<a href=“{url}"> <xsl:value-of select="label"/></a>





136

Modularization with Templates

• XSL can be divided into multiple templates using:• Call by name

<xsl:call-template name=“template_name"/>• By using XML tree select statements:

– <xsl:apply-templates select=“book"/><xsl:template match="/"> <html> <body> <xsl:apply-templates /> </body> </html></xsl:template><xsl:template match=“book"> <h1>Book Information</h1> <xsl:apply-templates select=“title" /></xsl:template>





137

xsl:apply-templates

• Apply template rule – current element – current element’s child nodes

• Optional: select attribute, – Applies the template rule only to the child that matches

• Multiple <xsl:apply-templates> – Select attributes– the child nodes are processed in the same order as the

<xsl:apply-templates> elements





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When templates are ignored

• A template is skipped if it does not apply• Use select="/“ to always process

– If it didn’t, nothing would ever happen

Warning:

If a template applies to an element, templates are not automatically applied to its children





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<xsl:template match="/"> <html> <head></head> <body> <b><xsl:value-of select="/book/title" /> </b> <xsl:apply-templates select="/book/author" /> </body> </html></xsl:template>

<xsl:template match="/book/author"> by <i><xsl:value-of select="." /></i></xsl:template>

Applying templates to children

<book> <title>Les Miserables</title> <author>Victor Hugo</author>

</book>

With apply-template line:Les Miserables by Victor Hugo

Without apply-template line:Les Miserables





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Calling named templates

• You can name a template, then call it, similar to the way you would call a method in Java

• The named template: <xsl:template name="myTemplateName"> ...body of template... </xsl:template>

• A call to the template: <xsl:call-template name="myTemplateName"/>

• Or: <xsl:call-template name="myTemplateName"> ...parameters... </xsl:call-template>





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Templates with parameters

<xsl:call-template name="showPeople"> <xsl:with-param name=“title" select="/project/title'"/> <xsl:with-param name=“people"

select="/project/team/members"/></xsl:call-template>

• Parameterized template:<xsl:template name="showPeople"> <xsl:param name="title"/> <xsl:param name="people"/> ...template body...refer to parameters as "$title" and "$people"

</xsl:template>– Parameters are matched up by name, not by position





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Generating XSL output with Java

Basic procedure for XSL transformation with Xalan:2. Instantiate a TransformerFactory

– Use the TransformerFactory static newInstance()

3. Generate a Transformer from XSLT source– TransformerFactory newTransformer(Source stylesheet)– Template

4. Apply transformation– transform(Source xmlSource, Result transformResult)– The Templates object to the XML Source





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• XSL and XSL constructs• Transforming XML document into different types of

documents





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Hands-On Lab

• Create an XSLT to create the Web page from XML– objectshop.xml– objectshop.xsl

• Use CSS to create the presentation– objectshop.css

Date post:	22-Jul-2018
Category:	Documents
Upload:	lamanh
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